Background: Encapsulation after Ahmed glaucoma valve (AGV) is difficult to manage and sometimes results in treatment failure. We proposed a novel conjunctival revision method to improve intraocular pressure (IOP) control due to encapsulation after AGV implantation. The efficacy and safety of this method in refractory glaucoma patients were evaluated. Methods: The present study was done in a clinical trial design. Patients of encapsulation after AGV implantation for at least 6 months were enrolled and divided into three groups (control group, single revision group, and repeated revision group). Characteristics such as visual acuity, glaucoma type, IOP change, underlying diabetes mellitus, and complications were assessed. Results: In total, 120 patients were enrolled in this study, and they were randomly divided into three groups on a 1:1:1 base. At the study end, there were 28 patients in the control group, 32 patients in single revision group and 37 patients in repeated revision group. The results showed that the conjunctival revision method significantly reduced the mean IOP of the encapsulated eyes on day 1 after the procedure (24.5 ± 6.3 to 11.8 ± 3.4 mmHg in single revision group and 25.1 ± 4.7 to 10.2 ± 2.3 mmHg in repeated revision group, respectively). The eye pressure was remained relatively low during follow-up visits for 4.17 ± 4.2 months in single revision group, whereas stable IOP could be maintained in repeated revision group for 10.43 ± 3.7 months in average. Changes in preoperative and postoperative visual acuities and the refraction errors were insignificant. Only mild complications occurred and most resolved without treatment. Conclusions: The conjunctival revision could relieve entrapped subconjunctival aqueous and therefore reduced IOP temporarily with single procedure, and IOP could be maintained with repeated procedures. This method is suggested to be a safe and simple alternative for refractory glaucoma patients developed encapsulation after AGV implantation.